TL;DR:
A slow iPhone is almost never dying hardware. In most cases it is full storage, a worn battery that makes iOS limit performance on purpose, background activity, or an old iOS version, and all four are fixable free in about 20 minutes. Work through the ten fixes below in order, storage first and the factory reset last, and stop when the phone feels fast again. Every menu path is checked against Apple’s own support pages.
Published: 3 November 2026. Last checked: 9 November 2026.
Why has your iPhone slowed down?
In most cases one of four things: storage that is nearly full, a battery worn enough for iOS to limit peak performance, background activity from apps refreshing and downloading, or an old iOS version missing performance fixes. Dying hardware is the rarest cause, which is why the fixes below start with storage and battery.
Apple’s own battery and performance page explains the second cause in detail: iOS watches the battery’s condition and, when it can no longer deliver peak power, manages performance to keep the phone running. That is protective, not a fault, and it is why two identical iPhones can feel completely different. The fixes below take the causes in order, and every one of them is free.
Which fix should you try first?
Storage, because a nearly full iPhone leaves iOS no room for the caches and temporary files it works with, and everything from app launches to the camera slows down. Open Settings, then General, then iPhone Storage, work through its recommendations, and keep a few gigabytes, roughly 5 to 10 percent of capacity, free.
The iPhone Storage screen shows a colour-coded bar and every app’s footprint. Work through it in this order:
- Review large attachments. Tap Messages or WhatsApp in the list and use Review Large Attachments. Old videos in chat threads are often gigabytes of dead weight.
- Offload unused apps. Turn on Offload Unused Apps at the top of the screen. Apple is clear about what this does: it frees the storage the app uses but keeps its documents and data, so nothing is lost and the app returns as it was when you tap its icon again.
- Delete downloaded media. Check the TV, Music and Podcasts apps for episodes and films you have already finished.
If photos are the real problem, moving them beats deleting them: our free cloud storage comparison covers where they can go, and compressing images without losing quality shrinks the library that stays on the phone. Many people find this single step fixes their slowness completely.
Does restarting and updating iOS really help?
Yes, and both take minutes. A restart clears temporary files and stuck processes, and if you have not restarted in weeks it is worth doing before anything else. iOS updates regularly include performance and bug fixes, so install the pending one from Software Update, on Wi-Fi and plugged in, and expect a few slower hours afterwards while the phone re-indexes.
To restart: on iPhones with Face ID, hold the side button and either volume button, drag the power-off slider, wait 30 seconds, then hold the side button until the Apple logo appears. On iPhones with a Home button, hold the side or top button and do the same. Then go to Settings, General, Software Update and install what is waiting. As of November 2026 the current public release is iOS 27.2, released on 26 October 2026, so if Software Update offers it, install it before trying the deeper fixes below. One caution for very old models: if your iPhone is more than about six years old, check what owners of the same model report about the newest iOS before a major update. Minor updates are always safe to take.
Which background settings should you change?
Background App Refresh is the one that matters. In Settings, General, Background App Refresh, turn it off for games, shopping and social apps you open manually anyway, or set it to Wi-Fi only. And skip the force-closing habit: Apple says switcher apps sit in standby, not running, and you should force one to close only if it is unresponsive.
The three global choices are Off, Wi-Fi, and Wi-Fi and Mobile Data. Off is the maximum saving; Wi-Fi is the sensible middle ground for most people. Push notifications still arrive with refresh off, because they travel a separate route; what changes is that feeds and inboxes update when you open the app instead of before. As for force-closing, quitting an app removes it from standby, so the next launch is a full cold start that is slower and uses more power, the opposite of the intended effect.
What if only web browsing feels slow?
Then clear Safari’s stored website data, which grows quietly over months. Go to Settings, Apps, Safari, and tap Clear History and Website Data, choosing All History for the fullest clean. You will be signed out of websites, so know your important passwords first; Apple notes your AutoFill information is not changed by clearing.
On iOS 17 and earlier the same option sits one level up, at Settings, Safari. If only one site misbehaves, remove just its data under Advanced, Website Data on the same screen. Other browsers keep their own data, so clear Chrome or Firefox from inside that app’s settings. Apple documents the whole process on its Safari support page.
Do Reduce Motion and Reduce Transparency make an iPhone faster?
They make it feel faster rather than making the processor quicker. Reduce Motion, in Settings, Accessibility, Motion, replaces long animations with quick fades, and Reduce Transparency, under Accessibility, Display and Text Size, cuts the blur effects the graphics chip has to draw. On older models the difference in everyday swiping and opening is obvious within a minute.
Nothing here deletes or changes your content, and both switches reverse instantly from the same screens if you prefer the polished look. Treat this pair as the last cosmetic step: worth doing on an older phone, after storage and battery, not instead of them.
Could your battery be the real problem?
Yes, and it is the cause most people miss. When an iPhone battery wears, iOS deliberately limits peak performance to prevent unexpected shutdowns, which feels exactly like a slow phone. Check Settings, Battery, Battery Health and Charging, labelled Battery Health on iPhone 15 and later, and read Maximum Capacity plus the Peak Performance Capability message underneath it.
Apple designs iPhone batteries to retain 80 percent of their original capacity at 500 complete charge cycles for iPhone 14 and earlier, and at 1,000 cycles for iPhone 15. Below roughly 80 percent, or when that Peak Performance Capability message says performance management has been applied, a battery replacement is the fix that restores full speed, at a fraction of a new phone’s cost. You can disable performance management from the same screen, but Apple warns the shutdowns it prevents may return. To slow the next battery’s ageing, use the charging options found there too: a charge limit on iPhone 15 and later, Optimised Battery Charging on earlier models.
How do you find one app that is slowing everything down?
Open Settings, Battery, and scroll to the usage by app for the last 24 hours and 10 days. An app using far more battery than your actual time in it is misbehaving: update it from the App Store first, restrict its background refresh next, and if it still misbehaves, delete it and use its website for a week to compare.
Social and shopping apps are the usual offenders, often because of a buggy update rather than the app itself, which is why updating comes before deleting. Also check the app still supports your iOS version: developers abandon old apps, and an abandoned app on a new iOS is a common source of freezes that no setting will cure.
What if none of that worked?
Reset the settings, not the phone. Reset All Settings, under Settings, General, Transfer or Reset iPhone, restores system preferences, network settings and privacy permissions to defaults without deleting apps, photos or messages. Only if that fails should you erase and restore, and only after a backup, using Erase All Content and Settings on the same screen.
Budget ten minutes after a settings reset to re-enter Wi-Fi passwords and re-allow app permissions. Before any erase, back up first, following our guide to backing up your phone, and let the backup finish before you touch Erase. If even a fresh restore feels slow, the limit is hardware, and the honest choices are a battery service or a newer phone.
Frequently asked questions
Does force-closing apps make an iPhone faster?
No. Apple says the apps you see in the switcher are not open; they are in standby to help you navigate, and you should force an app to close only when it is unresponsive. Quitting apps routinely makes the next launch slower, because the phone loads everything from scratch instead of resuming from standby.
How much storage should you keep free on an iPhone?
A few gigabytes, roughly 5 to 10 percent of capacity, is a sensible working rule rather than an Apple specification. It leaves room for caches, updates and the temporary files iOS juggles daily. The recommendations at the top of the iPhone Storage screen do most of the work: follow them and the free space usually takes care of itself.
Will erasing your iPhone delete everything?
Erase All Content and Settings removes everything, which is why you back up first and restore from that backup during setup. Reset All Settings is the gentler option with a similar name: it deletes no apps, photos or messages, only preferences such as Wi-Fi passwords, wallpaper and privacy permissions, which you then set up again.
When is a slow iPhone not worth fixing?
When a fresh restore still feels slow and the model no longer receives iOS updates, replacement beats repair, because new apps will only get heavier. The exception is the battery: if Battery Health is the problem, a replacement battery routinely makes an old iPhone feel new again, so price that before pricing a phone.
What is the fastest way to speed up an iPhone?
If you want to know how to make a phone faster, iPhone models respond best to three fixes: free up storage until at least 10 percent is empty, install the pending iOS update, and restart. Those three fix most slowdowns in about 20 minutes; work through the ten fixes above only if the phone still feels slow afterwards.
What should you do today?
Work through the fixes in order, storage first, and stop the moment the phone feels fast again; for most people the first four are enough and take less time than a trip to a repair shop. After that, a monthly habit keeps it fast: one storage check, one restart, and a glance at Battery Health every few months.
The same order of thinking works on your other devices: our guides to speeding up an Android phone and speeding up a slow Windows laptop follow the same logic of storage first, honest causes, and the reset only as a last resort.
